I think you should try to develop the membership program by giving additional
value for members. Some suggestions:
1. Cloud disk space like Ubuntu one have. Maybe code a simple native to
Trisquel interface for it.
2. Consider as a community to give support to mainly members only. That is,
you can give support to non-members and it would be good to do, but pay
special attention to supporting members. Optimally no problem a member have
should be left unsolved.
3. Think Penguin should give a one year Trisquel membership for those buying
a Trisquel machine.
Something even more radical could be to give compiled new versions of
Trisquel to members first and later to non-members. This could though
backfire. If done however, then a member should get a new version of Trisquel
at laters one month after Ubuntu it is based on is released.